The objective of this project is to use gas chromatography-mass spectroscopy (GC/MS) as a complementary analytical technique to 13C NMR spectroscopy to study metabolic pathways using biological mass isotopomers. With the recent acquisition of an Ion Trap GC/MS system at the Rogers MR Center, this project has been restructured with Shawn Roach as the P.I. and Dr. Paul Lee as the co-investigator. Several goals have been identified for this project: interpreting the MS spectra of glutamate isotopomers using known standards and biological samples; comparison of MS experimental data with tcaSIM predictions; and determination of fractional enrichment data from MS and comparing this data with 1H and 13C NMR data. Additional long-term goals include examination of additional information provided by GC/MS of other amino acids as well as from tandem MS experiments.